The worst of the violence struck the capital Kabul, when at least one suicide bomber detonated explosives near the Abul Fazel shrine as Shi'ite worshipers gathered. The blast killed 55 people - including women and children - and wounded 160 others.

A second explosion, taking place on Ashura, targeted a shrine in Mazar-e-Sharif, the capital of northern Balkh province, killing four people. It is not clear whether Shi'ites were the specific target.

Afghan President Hamid Karzai, still in Germany following international conference on Afghanistan on December 5, condemned the attacks and cancelled his planned two-day visit to Britain to return home.  He said "this was the first time that on such an important religious day in Afghanistan terrorism of that horrible nature had taken place."

The Taliban denied involvement in the attacks, calling them "cruel and indiscriminate" and blaming them on the "invading enemy."

However, the Pakistan-based insurgent group Lashkar-e-Jhangvi al-Alami claimed responsibility for the Kabul attack. The Sunni extremist group is an offshoot of the bigger Lashkar-e-Jhangvi, which is affiliated with al-Qaida and is responsible for a number of attacks against Shi'ites in Pakistan.

United Nations Secretary-General Ban Ki-moon also condemned in the strongest terms "such indiscriminate attacks against civilians and extended his deepest condolences to the families of the victims."